Talk:Building the Impossible!
Made of aluminium? So the Rapture is made of aluminium? 17:26, April 5, 2014 (UTC) Stronger than Steel by weight, but weight really isnt an issue (for planes it is) But it (aluminium) did cost more than steel (quite a bit more) . And the quantities used would probably get even more government attention than steel being used. But then only part of the structures is the metal and the bulk would likely be concrete, as you need compression strength to withstand the water pressure. Building on the surface... Logical to do prefabrication where it is easier at surface or even back on land, and not at some deep depth where complications multiply manyfold and special equipment is needed for everything - deep diving hard suits are NOT used by joe-blow workers. Less and less excuse for so many 'construction workers' to be allowed into Rapture (they are used in the plot as the excuse for all the 'poor' 'downtrodden' 'out of work' people who cause so many issues. If they worked on the surface/on land then they really never had to see Rapture (and could be prevented really from knowing where it was), so didnt have to be allowed to live there 'so they wouldnt reveal the secret'. Most of the 'construction workers' who were let below then would be more machine operators and technical people versus manhandling grunts/gophers. The ones let in would also be told that construction would evenbtually end and they had better be ready to take up new professions (city maintenance would absorb more than a few doing similar type jobs). - Building a city the size of Rapture, even in prefab form, on the coast, would have been noticed by the government. Getting the prefab sections out to the ocean site on barges in good weather, sink them and construct them underwater (a whole city) without being noticed would be highly unlikely. Also the cost and effort involved in moving a city from the land to the seabed, hundreds of miles away would be counterproductive. A more realistic way to build an underwater city would be to make a large prefab factory on land which could be assembled on the ocean floor. This underwater factory would then make a small town to house the workers to make the prefab buildings of rapture. It might even be possible to build an underwater steelworks if the right ores are available locally. Moving millions of tons of steel girders and all the other steel structures from the land hundreds of miles in good weather and at great cost would be counterproductive. Rapture would most likely have been a small industrial mining, steel and construction town at first. This industrial site/town would have built the entire infrastructure needed as the city was built in large factory hangers with large airlocks to get the prefab sections onto the prepared seabed. The ocean floor mud could have been refined into concrete, as the mud would contain micro fossil carbonates etc. A power plant might have been one of the first things needed to be built, to supply power to the mines, mills, construction works and factories. I think that it is highly unlikely that a whole city could be built on land and then sunk down into the ocean, even in prefab form. There would also be many food related jobs like farming, fishing, harvesting and food processing for the ex constrution workers. - If Ryan had businesses building drilling rigs or something similar, that would help, but he could also just have the 'parts' built for 'building construction' in one city and shipped by water (parts too big for Railroad transport) and just have them keep going out to sea. It depends how large the prefabricated sections are. Sections of wall panels, the struts between the walls which compress to oppose the water pressure, etc.. are still only 'pieces' and can look fairly generic. Now THOSE can be assembled into larger assemblies on site (That Lighthouse means there IS a shallow zone where IT is possible to do alot of work at/near the surface or partially on land), thus into sections of buildings, which either could be lowered down to assemble into Rapture's buildings, or possibly smaller buildings could be assmbled almost entirely at the Surface (the work at less than 100 feet can use normal diving equipment, while at city depth, it requires really complex diving hardsuits - and ADAM doesnt exist at this point to bypass that fact). Anything on the ocean floor ITSELF has to be constructed. Factory just adds to the overhead. Most raw materials just wont be avialable 'locally'. Sorry, no steel-plant -- the ores adaquate to make steel (and the limestone and coke and other fuel) all come only from limited places on land to make steel of a large amount, practically. So you might as well produce it there and ship it (which BTW will take a fleet of ships and not just 'The Olympian'). And if you are worried about the shipping , shipping all that even bigger bulk of raw material would be EVEN more expensive to be shipped (besides the difficulty of any steel-plant actually working (oh and another thing steel-making needs is ALOT of air). And it is Thousands, of miles, not hundreds to transport to Rapture.... And as I mention the premaade steel/aluminium components are nowhere near as big a mass as the amount of concrete that would also be used (the aggregate - rock/sand) might really be the only locally available materials. Cement, like the steel, is much easier/cheaper to make at efficient land cement plants, with optimal materials (the fuel to make cement is also one of its bulkier raw materials... assuming you had any of the othere proper materials to 'refine' it from locally ). Dont worry there is still alot of work to do down below. The prefab talked about so far is just the structural shells of the buildings and those have to be joined to the foundation and made water tight and pressure resistant. There are the interiors to be installed once they are pumped out and dry and cleaned. There are many miles of pipes/conduits/venting/cabling to be installed and connected. Lots and lots of machinery that needs to be in the buildings. All the carpentry/plastering work has to be done to the inside. ''lunette ring'' Strange for this to be included (Ryan saying it) only really there for the detail in the plot (the place where the Quantum thingee needs to be put (actually fastened securely) by Elizabeth. The words should be more something like it being lowered by/on cables. For the real task it would be multiple cables because ocean currents make things in water sway, tilt and even rotate (or to take off downcurrent at a good clip), which then requires MANY guide lines/cables and additional ships/tie locations on the surface to counter the effects of the ocean waters movement, so to land the building in its correct place on the seabed. Funny thing is - raising it (to somehow dock with some connection to Rapture -- its old spot ?) would require similar control against water movements -- good thing that the Quantum particle has steering and drive speed controls and that Elizabeth can see everything perfectly to 'kiss' the docking ports together within a few millimeters - Astronauts train for months to do that with computers and sensors aiding them, so good thing that Elizabeth manages to 'wing it' (maybe she learned how to do THAT by reading it in books like lockpicking...). 13:14, August 4, 2014 (UTC) Rapture is doomed because it's alluminum structure http://www.sv.vt.edu/classes/MSE2094_NoteBook/97ClassProj/anal/kelly/fatigue.html "The significance of the fatigue limit is that if the material is loaded below this stress, then it will not fail, regardless of the number of times it is loaded. Material such as aluminum, copper and magnesium do not show a fatigue limit, therefor they will fail at any stress and number of cycles." What this basicaly means is that the alluminum internal structure of Rapture's buildings WILL fail after awhile. And not a long time either. We are talking only a few decades. Alluminum's weakness is well known today (but unknown when Rapture was built). We hear in the news regularly that aircraft need to be inspected for cracks in their alluminum frames or on occation a plane crashing due to the failure of part of an alluminum part. Ryan should have used steel. A big question is why this audio log is in BaS Pt 2 at all though. ??? --Solarmech (talk) 07:25, August 5, 2014 (UTC) :The statement they have Ryan make doesnt make sense either - alot of steel was needed and that would be noticed by the government types OHHHH NOOOOS ... BADDDDDDD --- as if the same amount of (more expensive and more limited made) aluminum WOULD NOT be even MORE noticed (a cold war material used with aviation etc..) Huge atypical girders being made out of aluminium wouldnt be noticed or the huge quantities ??? :Actually alot of the building would need to be thick concrete for its compression ability (say 600 feet max is 20 atm of pressure ~280lb/in^2) requiring huge internal compression bracing. The metal would be around the windows (plus whatever magic material for the 'glass' panes -- some seen flat 20-30 ft across) and probably steel rebar (coated for in the concrete possibly some Ryan 'high tech' graphite fibers or somesuch to strengthen the concrete). : 10:48, August 5, 2014 (UTC) ::Actually the Rapture novel does have something called "Ryanium" for certain parts of Rapture. As you say Rapture would need a *lot* of concrete (which could be noticed), but this actually makes the situation worse. The alluminum structures would be buried inside all that concrete and no one could see it starting to fail. As for big alluminum girders those were probably being manufactured at a site Ryan owned. And so long as this stuff wasn't being shipped overseas the US govt, really wouldn't even care. Just working through a number of shell companies could hide a lot of what Ryan was doing. --Solarmech (talk) 11:22, August 5, 2014 (UTC) :::I suppose that the kind of stress and strain the buildings' structures would go through from the oscillating ocean currents (as well as the water pressure) might be comparable to the stress a plane goes through from hundreds of take offs and landings, but isn't the issue primarily the thickness of the aluminum? :::Don't get me wrong, building the city from aluminum is fucking stupid, but airplanes have to be so lightweight in order to achieve flight that the thickness of the metal is pretty thin compared to something like a skyscraper's girder. Isn't it possible that the thicker beams of the buildings would be less likely to crack? :::Unownshipper (talk) 02:56, August 6, 2014 (UTC) ::::Actually thicker beams means they would more likly to crack. (There are technical terms for all this but I can't remember them :( ) Say a beam bends to the right. The right side of the beam is compressed down a little and the left side stetched. The thicker the beam, the more the right side would be compressed and the left side stretched. Thinner beams would actually be better. But even then they WILL still fail do to progrssive weakening. --Solarmech (talk) 06:29, August 6, 2014 (UTC) ::::- ::::Plastic deformation and strain hardening and buckling? ::::One hopes that Rapture was largely out of direct ocean currents - protected by the undersea volcanoes side, though you still get turbulance eddies with some pockets in the terrain contours that would amplify those. Water is like 800 times denser than air, and a few miles an hour current's force then is multiplied by that factor. All those tall and thin buildings the artists liked showing is problematic, with the leverage along that length to multiply the bend forces at the buildings base (the tall spires/towers with their minimal interior space possible, might be decorative (Art Deco did that alot) and top 1/3rd of the structure more like a wiffle ball to let alot of the moving water pass through. ::::Steel and concrete would be more easily missed in Americas economy than aluminum (and the materials could be transshipped from around the globe too). ::::The prefabrication, even with a cover story for 'ahead of its time' deep-sea drilling rigs and such, would be made obviously strange looking by skyscraper like multitudes of windows typically shown in the skyboxes. Perhaps its more 'show' again with many fake lighted windows just for looks (and lower cost/complications) as the small windows ARE problematic to have in ~8 foot thick concrete walls. But then all kinds of cover-up tactics Ryans organization could think up. ::::Yes, the book author mentioned Ryanium (Scotty's Transparent Aluminum ??) which probably would be needed (in its transparent form) for the big windows... maybe it being something like earlier-than-real-world Polycarbonate. Best if curved, which few we saw windows were. Smaller windows maybe thick Pyrex or the equivalent of Gorilla Glass. ::::Maybe technologies that part of Ryan's billionaire status might be base on (high energy electrical processing / whatever) :::: 07:51, August 6, 2014 (UTC)